Let me go into more detail. Don't use the same browser for clearnet and tor. Never do this.

It's best to clear the data from whatever browser you use for tor every time you start it. The tor browser does this on it's own. It would be easy enough to correlate you via left-over browser data.

You should really be using the tor browser unless you have a specific need to not.

Don't use javascript unless you really need it. That can expose you. Not only that, but who wants to run untrusted code? This will break some sites.

Don't mix your lives. Your bank account should never be accessed over tor. Nor your facebook, twitter or whatever else. Unless that's the only way you ever access it. Think political bloggers in some less than free countries. It depends on your case use. But, never login with the same account on both networks.

Perfectly safe. I do it all the time.

Yes, but be smart about it.

Yes it's fine. Just make sure your browser turns off headers, or, you are using the tor browser. The security risk comes from the fact that some websites request the headers of what ever other tabs you happen to have open. Turning off header requests in firefox should solve this.

yes, fuck the government